Heat sealing composition, use thereof and closure plug made from said composition

ABSTRACT

The invention concerns a heat sealing composition including an adhesive framework and a framework forming constituent, the adhesive constituent being a maleic vinyl-anhydride ethylene-acetate polymer or a vinyl ethylene-acetate polymer modified to have epoxy functions and the framework forming constituent being selected from among a block polyether amide, modified or not, and a block polyether ester. The composition is useful for making closure plugs.

The invention relates to a thermogluing composition as well as to itsuse, in particular for the manufacture of a closing stopper for anyopening.

It also concerns a closing stopper for any opening consisting of thethermogluing composition of the invention.

Closing devices have already been proposed to stopper any opening, and,in particular, an opening in a metal part.

For example, closing devices have already been proposed which consist ofa plastic material based on polyethylene (PE) and polypropylene (PP), ora mixture of polypropylene and an ethylene-propylene-diene terpolymer(PP/EPDM).

Such a closing device consists of a body made of the desired plasticmaterial having the form of the opening to be closed and it comprises asingle or double sealing lip which is usually located in the extensionof the body of the closing device.

This closing device was placed in the opening to be closed without anysubsequent treatment. However, the seal of this closing device againstrun off water and dust is weak. In addition, when one applies pressureto this closing device in place, the seal is easily broken.

A closing device was then proposed which consists of a steel body and abead of hot melt deposited on the peripheral surface of the body.Hooking tabs are arranged at the periphery of the body of the closingdevice in order to maintain this closing device in place. Once theclosing device is positioned on the opening, the assembly is subjectedto a passage through an oven, and the glue constituting the bead of hotmelt melts and hardens during the cooling of the assembly. Thus, theseal between the closing device and the support of the opening has beenachieved. The hot melt used is a glue based on a copolymer ofethylene/vinyl acetate (EVA) and its derivatives.

However, the metal body of such a closing device raises problems duringits fitting in the opening to be closed because of its hardness and itslack of flexibility.

To avoid the problem caused by the metal body of the closing deviceitself, closing devices have also been proposed whose body is made of aplastic material and which comprise a bead of hot melt deposited on theperipheral surface of this body.

The seal of the closing device on the support comprising the opening tobe closed is achieved in the same manner as above by passage through anoven.

More specifically, such a closing device generally consists of a bodymade of polyamide 66 or of an alloy of polyamide and of polypropylene,and the bead of hot melt is a bead of glue based on a copolymer ofethylene-vinyl acetate and its derivatives.

This type of closing device with a bead of glue presents a good sealagainst run off water, dust, and pressure, but its manufacturing methodrequires a step for manufacturing the body and a step for manufacturingand positioning the bead of glue. This method is thus long andcomplicated to use, and it requires, in addition, a specific apparatus.

Thus, it is desirable to simplify the method of manufacturing this typeof closing device and to improve its reproducibility.

The invention is intended to overcome the above drawbacks of the closingdevices of the prior art by proposing a closing device which consists ofone and the same material which, at the time of passage through theoven, allows the closing of the opening, for example, of a metal plate,while at the same time achieving the desired seal against run off water,dust and pressure, and which can be manufactured at low cost, by asimple and reproducible method.

To this effect, the invention proposes a thermogluing composition of thetype comprising an adhesive component and a component forming aframework, characterized in that:

a) the adhesive compound is a polymer of ethylene-vinyl acetate(EVA)-maleic anhydride and/or polyethylene (PE) and/or polypropylene ormodified to have epoxy functions, and

b) the component which forms the framework is an ester block polyether(COPE) or an amide block polyether (PEBA) optionally mixed with acopolymer of ethylene/propylene, where said copolymer ofethylene-propylene can be replaced entirely or in part by a terpolymerof ethylene-propylene-diene (EPDM).

According to a characteristic of the composition of the invention, saidEVA-maleic anhydride contains 0.5-40 wt % of units of vinyl acetate and0.05-15 wt % of maleic anhydride, the remainder being ethylene.

More preferably, said EVA-maleic anhydride contains 5-25 wt % of unitsof vinyl acetate and 0.5-10 wt % of maleic anhydride, the remainderbeing ethylene. It is most preferred for said EVA-maleic anhydride tocontain 14 wt % of units of vinyl acetate and 0.5-1 wt % of maleicanhydride.

In a preferred embodiment variant, the polymer of ethylene-vinylacetate-maleic anhydride is a copolymer of ethylene-vinyl acetategrafted with maleic anhydride.

When the EVA is modified to have epoxy functions, the epoxy functionsare preferably contributed by glycidyl methacrylate.

The EVA then preferably contains 1-10 wt % of units of glycidylmethacrylate.

According to an embodiment variant of the composition of the invention,the component forming the framework is an ester block polyether (COPE)whose ester part consists of poly(butylene terephthalate) (PBTP) andwhose ether part consists of units of ethylene glycol and/or propyleneglycol.

According to another embodiment variant of the composition of theinvention, the framework material is PEBA mixed with a copolymer ofethylene-propylene and/or a terpolymer of ethylene-propylene diene, inwhich the PEBA consists of blocks of polyamide 6 and ether segmentsbased on ethylene glycol and/or propylene glycol, and the diene of theterpolymer of ethylene-propylene-diene, when present, is butadiene.

Preferably, in the compositions of the invention, the ratio by weightbetween said active component and said framework forming component isbetween 80:20 and 70:30.

When the framework forming component is an ester block polyether, thepreferred ratio by weight between the adhesive component and the esterblock polyether is preferably 60:40.

The preferred ratio by weight between the adhesive component and theframework forming component is 75:25, when the framework formingcomponent is a mixture of PEBA and of a copolymer of ethylene propyleneand/or EPDM.

The composition of the invention can, in addition, comprise additivessuch as resins that are sticky to the touch, fire retardant agents,reinforcement agents, antistatic agents, antifungicides [sic;fungicides], anticoagulation agents, stabilizers against decompositionby light or heat, dyes as well as fillers, alone or in mixtures ofseveral of them.

A preferred composition of the invention comprises in addition to theadhesive component and the framework forming component, a resin whichimparts stickiness to the touch at cold temperature.

Preferred resins that impart stickiness to the touch at cold temperatureare of the glycol ester type, such as diethylene glycol ester anddipropylene glycol ester.

In this case, the composition of the invention preferably contains0.2-10 wt % of resin which imparts stickiness to the touch, withreference to the total weight of the composition of the invention.

The invention also proposes a closing stopper for any opening made intoa metal support, which [stopper] embraces the composition of theinvention.

This closing stopper can consist in its entirety of the composition ofthe invention.

In particular, this closing stopper comprises a surface havingdimensions which are larger than those of the opening to be closed aswell as a means for hooking into said opening.

This closing stopper can consist in its entirety of the composition ofthe invention.

According to a preferred embodiment variant of the closing stopper ofthe invention, the latter consists of a plate which is made of amaterial having a melting-decomposition temperature which is higher thanthe maximum temperature reached during the passage through an oven whichis used to glue the stopper to its support, and which has dimensionswhich are larger than the opening to be closed on at least one of itsfaces, which plate is coated with a film made of a composition of theinvention containing a resin which is sticky to the touch at coldtemperature.

In this case, the preferred resin which presents stickiness to the touchat cold temperature is a resin of the glycol ester type. In particular,it is preferable to use a diethylene glycol ester or a propylene glycolester as resin which presents stickiness to the touch at coldtemperature.

In this case, the material constituting the plate can always be acomposition of the invention without resin which is sticky to the touch,a metal, an elastomer, a honeycombed elastomer, a rigid plastic,polytetrafluoroethylene, a hot melt composition containing an expansionagent which decomposes at a temperature higher than or equal to 140° C.

According to a characteristic of the closing stopper according to thisembodiment variant, the plate has a thickness of 0.5-5 mm, and the filmhas a thickness of 0.3-3 mm.

The invention also covers the use of the composition of the inventionfor the manufacture of a stopper to close any opening of any type ofsupport or any other type of industrial product.

The invention will be better understood, and other purposes,characteristics and advantages of the latter will become more apparentin the following detailed description which is made with reference tothe drawings in the appendix which are only given as examples, and inwhich:

FIG. 1A is a perspective view and a bottom side view of a stopper of theprior art;

FIG. 1B is a side elevation of the closing device represented in FIG.1A, but in a position mounted on the metal support;

FIG. 2A is a bottom view, in perspective, of another closing deviceaccording to the prior art comprising a bead of glue which isrepresented separately in this figure;

FIG. 2B is a perspective view, from below, of the closing device of FIG.2A represented with the bead of glue in place on the closing device;

FIG. 2C is a perspective view of the top side of the closing devicerepresented in FIG. 2B mounted on a metal support;

FIG. 2D is a side elevation of the closing device visible in FIG. 2C;

FIG. 3A is a bottom view in perspective of a first embodiment variant ofthe closing device according to the invention;

FIG. 3B is a perspective side view of the closing device represented inFIG. 3A mounted on a metal support;

FIG. 3C is a side view of the closing device of FIG. 3B;

FIG. 3D is an elevation view of the closing device of FIG. 3A;

FIG. 3E is a cross-sectional view along the line IIIE—IIIE of FIG. 3D;

FIG. 3F is a top view of the closing device along the arrow IIIF of FIG.3E;

FIG. 3G is a top view of a variant of the closing device;

FIG. 3H is a cross-sectional view along the line IIIH—IIIH of FIG. 3G,of a variant of the closing device without hooking tab;

FIG. 4A is a cross-sectional side view of another variant of the closingdevice of the invention;

FIG. 4B is a cross-sectional side view of yet another variant of aclosing device of the invention;

FIG. 5 is a photograph illustrating the results of temperatureresistance tests carried out on a thermogluing composition which doesnot enter in the context of the invention;

FIG. 6A is a photograph which allows comparing a closing devicemanufactured with a composition which does not enter in the context ofthe invention (sample 5B) with a closing device manufactured with acomposition according to the invention (sample 8B), after passagethrough an oven;

FIG. 6B is a photograph which allows a comparison of a closing devicemanufactured from a composition which enters in the context of theinvention before and after passage through an oven;

FIG. 7 is a photograph taken from above of another closing devicemanufactured from another composition which enters in the context of theinvention and which is mounted on a support, before passage and afterpassage through an oven;

FIG. 8A is a diagrammatic elevation view of a testing apparatus whichallows the measurement of the water sealing of a closing device testedin the vertical position;

FIG. 8B represents the same testing apparatus to measure the watersealing of a closing device tested in the horizontal position;

FIG. 9 is an elevation and a cross-sectional view of a test apparatusfor testing the resistance to detachment, used to test closing devices;

FIG. 10A is a diagrammatic view of a specimen, before passage through anoven, for the determination of the shrinkage of the composition;

FIG. 10B is a diagrammatic plan view of a specimen after passage throughan oven, for the measurement of the shrinkage of the composition;

FIG. 11A is a diagrammatic cross-sectional side view of a specimenmanufactured from a thermogluing composition, mounted above an openingon a metal support, before passage through an oven; and

FIG. 11B is a cross-sectional view similar to FIG. 11A but after passagethrough an oven, to measure the deflection of tested specimens.

For a better understanding of the invention, closing devices of theprior art will be described first.

With reference to FIGS. 1A and 1B, an embodiment example of asingle-material closing device of the prior art consists of one and thesame plastic material and essentially comprises a sealing lip 2, a body1, and hooking tabs 3. The body 1 has essentially the same diameter asthe opening to be closed in a, preferably metal, support, and thesealing lips 2, as shown in FIG. 1B project above the metal support 4while the hooking tabs 3 maintain the closing stopper in place byhooking inside the opening and below the metal support 4.

As already stated, such closing device, which is maintained in placeonly by its hooking tabs, presents only a very weak seal against waterand dust, and no pressure seal. Indeed, by simply applying manualpressure, the closing stopper can be made to come out of the opening tobe closed.

To solve this sealing problem, another closing device has been proposedin the prior art, as shown in FIGS. 2A, 2B, 2C and 2D. Thistwo-component closing device essentially comprises a body 1 made ofplastic material or a metal having essentially the shape and thedimensions of the opening to be closed, sealing lips 2 formed from thesame material as the body 1 and having dimensions larger than theopening to be closed, and hooking tabs 3 made of the same material asthe body 1 and the sealing lips 2.

As shown in FIG. 2A, this closing device of the prior art comprises, inaddition, an annular body of glue 5 represented separately in FIG. 2Aand represented in mounted position on the closing device in FIG. 2B.This closing stopper with the mounted annular body of glue is thenplaced on the opening of the metal support 4 to be closed with thehooking tabs inserted in the opening and maintaining the closing devicein position by hooking under the metal support 4. The assembly is thenpassed through an oven at a temperature which causes the melting of theglue which hardens and adheres to the metal support and to the body ofthe opening device during the cooling which follows after the removalfrom the oven.

The glue generally consists of a melt adhesive, also called hot melt inthe art, which is an adhesive based on a copolymer of ethylene-vinylacetate (EVA) and its derivatives. As also already stated, the sealagainst water, dust and pressure of this closing device is good, but itsmethod of manufacturing is complex, raises problems of reproducibility,and requires special equipment.

In this closing device of the prior art, the body 1 can consist of ametal or a plastic material.

When the body 1 is made of plastic, the materials which are generallyused to manufacture this body belong to the polyamide 66 series or theseries of alloys of polyamide and polypropylene.

It should be noted that the manufacturing cost of such two-componentclosing devices is high.

Consequently, there is a need in the prior art for a closing deviceconsisting of a material which can be readily molded in any desiredform, which is flexible so that it can easily be inserted in an openingto be closed; which after passage through an oven adheres to the metalsupport, one opening of which is to be closed, without presentingexcessive deformation at high temperatures; and which adheres to anytype of support, particularly a metal support.

In other words, the invention is intended to provide a thermogluingcomposition:

which is easy to use and shape,

which undergoes, without chemical alteration, a first heating step for15-30 min at 140° C. and a second heating step for 30-45 min at 195° C.,which are the minimum and maximum time/temperature pairs achieved inovens that are currently used in the industry to achieve the adhesion ofa closing stopper to metal supports,

which adheres to any type of support, particularly a metal support,after these heating cycles,

which is easy to mold,

which does not deform or deforms only little after having been subjectedto one or more passages through an oven at the temperatures and for thetime periods defined above, and

which after the passages through an oven, as defined above, and afterhaving been placed above an orifice to be closed, adheres to the supportand does not undergo any deformation, and which presents a seal to waterfor at least 1 h at a minimum pressure of 0.1 bar.

In addition, this thermogluing composition, after it is molded to form aclosing device and is glued to the support, must not lose its quality ofadhesion, its water and pressure seal, and it must maintain its shape,even if the temperature to which this closing device is subjected variesfrom −40° C. to +80° C., a range which represents the conditions of useconsidered for the metal parts requiring the closing devices of theinvention.

The thermogluing composition according to the invention consists of twocomponents, namely an adhesive mixture characterized by a meltingtemperature less than the minimum temperature of the ovens currentlyused, that is 140° C., and a second component called “frameworkmaterial” characterized by a melting point which is higher than themaximum temperature which can currently be achieved in an oven, that is195° C. The adhesive mixture will make it possible to glue the closingstopper made from the thermogluing composition of the invention to themetal support comprising the opening to be closed, to maintain in placethe closing device and to ensure the desired water, dust and pressureseal, while the framework material will make it possible tosubstantially maintain the shape and the dimensions of the closingstopper made from the thermogluing composition of the invention, duringthe operation of melting the adhesive and thus gluing the closingstopper to the metal support.

After numerous tests on different compositions of the type comprising anadhesive and a framework forming material, it was discovered that athermogluing composition comprising:

as adhesive mixture, either a copolymer of ethylene-vinyl acetate(EVA)-maleic acid, optionally also modified with polyethylene and/orpolypropylene, or a copolymer of ethylene/vinyl acetate modified to haveepoxy functions and

as framework component, either an amide block polyether (PEBA)optionally modified by a copolymer of ethylene-propylene and/orterpolymer of ethylene-propylene-diene (EPDM), or an ester blockpolyether (COPE),

made it possible to produce a closing device having all the abovedescribed required properties.

In the composition of the invention, the adhesive mixture used is thecopolymer ethylene-vinyl acetate-maleic anhydride obtained either by adirect polymerization of the starting monomers, or by grafting of thedesired quantity of maleic anhydride to the copolymer of ethylene/vinylacetate.

In addition, this polymer can optionally be modified with polyethyleneand polypropylene, which themselves may optionally be grafted withmaleic anhydride.

Different tests were carried out to demonstrate the superior propertiesof the composition of the invention in comparison to compositions whichdo not enter in the context of the invention

Thus, different compositions comprising different adhesives anddifferent framework materials as shown in Table 1 below were firsttested with regard to deformation at high temperature. These tests arecarried out on rectangular platelets having dimensions, before the test,of 50 mm×40 mm, and a thickness of 2.0 mm. First, these platelets wereplaced on a perforated metal plate. The hole of the metal plate isoblong and has the dimensions 20 mm×40 mm, as shown in FIG. 5.

The specimens, each having the composition shown in Table 1, were eachplaced on a perforated plate and passed through an oven, first at lowtemperature, that is 140° C., for 30 min, and then at high temperature,that is 195° C. for 30 min, which are the time/temperature pairs chosenas representative of those currently used.

A visual evaluation was then carried out:

1) If, after each of these thermal treatment cycles, the compositionmaintains a sufficient viscosity so as not to flow through theperforated plate;

2) If the adhesion to the metal support constituted by the perforatedplate is sufficient;

3) If the shrinkage is acceptable for the desired closing function (sealmaintained);

4) If the deflection of the specimen through the hole is acceptable.

FIG. 5 is a photograph of the results of these tests carried out onspecimens whose composition does not enter in the context of theinvention.

Thus, one can note that these compositions which do not enter in thecontext of the invention do not succeed in producing, at the time of apassage through an oven at 195° C. for 30 min, the desired closurefunction since all the specimens have melted and passed through theoblong [perforation] of the perforated plate.

The ratio by weight of the adhesive to the framework component was 25:75for each one of these samples.

The different adhesives tested are:

A: Copolymer of ethylene-vinyl acetate, noted EVA in Table 1.

B: Copolymer of ethylene-vinyl acetate grafted with maleic anhydride,noted B in Table 1. This adhesive is the one selected in the invention,because it is the one with which the best results are obtained when itis used with the framework composition selected in the invention, asproven by the results of different tests which will be explained below.

C: Copolymer of ethylene-acrylic ester.

D: Terpolymer of ethylene-acrylic ester-maleic anhydride.

Different framework components are also tested in a mixture with eachone of the above adhesives. These framework components are thefollowing:

1. Polyamide 6, noted PA 6 in Table 1.

2. Polyamide 66, noted PA 66 in Table 1.

3. Polyamide 11, noted PA 11 in Table 1.

4. Amide block polyether, noted PEBA in Table 1. It is one of theframework components selected in the composition of the invention.

5. Alloy of polyamide and polypropylene noted alloy PA/PP in Table 1.

6. Polyoxymethylene noted POM in Table 1.

7. Mixture of propylene and of a terpolymer of ethylene-propylene-diene,noted PP/EPDM in Table 1.

8. Ester block polyether noted COPE in Table 1. This framework componentis one of those selected from the composition of the invention.

9. Terpolymer of acrylonitrile-butadiene-styrene, noted ABS in Table 1.

Each one of the tested compositions was referenced by a numeral followedby a capital letter. This numeral corresponds to the nature of theframework component as identified above and the capital lettercorresponds to the adhesive as identified above.

Thus, the sample 1A is a sample prepared from a composition comprising75 wt % of a copolymer of ethylene-vinyl acetate and 25 wt % ofpolyamide 6, and sample 4D corresponds to a composition comprising 75 wt% of a copolymner of ethylene-vinyl acetate grafted with maleicanhydride as adhesive and 25 wt % of amide block polyether as frameworkcomponent.

These references are used throughout the entire description given below,and in the tables which follow, and they always represent the samecompositions.

Table 1 below shows each one of the compositions so tested.

TABLE 1 Terpolymer EVA modi- Copolymer ethylene- fied with ethylene-acrylic Ad- EVA maleic acrylic ester-maleic framework hesive Aanhydride, B ester, C anhydride, D PA 6 1 1A 1B 1C 1D PA 66 2 2A 2B 2C2D PA 11 3 3A 3B 3C 3D PEBA 4 4A 4B 4C 4D Alloy PA/PP 5 5A 5B 5C 5D POM6 6A 6B 6C 6D PP/EPDM 7 7A 7B 7C 7D COPE 8 8A 8B 8C 8D ABS 9 9A 9B 9C 9D

The results of the visual observations that were carried out on each ofthe samples shown in Table 1 after passage through the oven for 30 minat 140° C., and then passage through the oven for 30 min at 195° C., areregrouped in Table 2 below.

TABLE 2 After 30 min. at 140° C. After 30 min. at 195° C. PassagePassage Sam- through through Other ple the plate Adhesion ShrinkageDeflection Other observations the plate Adhesion Shrinkage Deflectionobservations 1A No Poor Moderate Not measured Not sealing No Good WeakAcceptable Turns yellow 1B No Acceptable Moderate Not measured No GoodWeak Acceptable Turns yellow 1C No Acceptable Moderate Not measured NoGood Weak Acceptable Turns yellow 1D No Poor Strong Not measured Notsealing No Good Strong Acceptable Turns yellow 2A No Acceptable Weak Notmeasured No Good Weak Acceptable 2B No Acceptable Strong Not measured NoGood Strong Acceptable 2C No Acceptable Weak Not measured No Good WeakAcceptable 2D No Acceptable Moderate Not measured No Good Strong 3A NoAcceptable Weak Not measured Yes Not Measurable 3B No Acceptable WeakNot measured Yes Not Measurable 3C No Acceptable Weak Not measured YesNot Measurable 3D No Acceptable Weak Not measured Yes Not Measurable 4ANo Acceptable Strong No change in color No Good Very weak High Yellowcolor 4B No Acceptable Weak No change in color No Good Weak AcceptableYellow color 4C No Acceptable Weak No change in color No Good WeakAcceptable Yellow color 4D No Acceptable Strong No change in color NoGood Strong Weak Yellow color 5A No Acceptable Weak Acceptable No changein color No Good Weak Acceptable Pink 5B No Acceptable Weak AcceptableNo change in color No Good Weak High Pink 5C No Acceptable Strong HighNo change in color No Good Strong High Pink 5D No Acceptable Strong HighNo change in color No Good Moderate Weak Pink 6A No Acceptable None ZeroYes Not measurable 6B No Acceptable None Zero Yes Not measurable 6C NoAcceptable None Zero Yes Not measurable 6D No Acceptable None Zero YesNot meaurable 7A Yes Yes Not meaured 7B No Acceptable Moderate High YesNot meaured 7C Yes Yes Not meaured 7D Yes Yes Not meaured 8A No Zero NoAcceptable Very weak Zero 8B No Acceptable Very weak Zero No AcceptableVery weak Zero 8C No Zero Very weak Zero No Acceptable Very weak Zero 8DNo Acceptable Very weak Zero No Acceptable Very weak Zero 9A NoAcceptable Moderate Very high Yes Not measured 9B No Acceptable StrongModerate Yes Not measured 9C No Acceptable Strong Moderate Yes Notmeasured 9D No Acceptable Strong Moderate Yes Not measured

As one can see from Table 2, the compositions in which the frameworkmaterial is polymide 11, a mixture of polypropylene and of a terpolymerof ethylene-propylene-diene or of acrylonitrile-butadiene-styrene,cannot be used because they melt during the passage through the oveneither at low or at high temperature.

The shrinkage measurements were only carried out on the remainingsamples, that is the samples in which the framework was either PA 6(series 1A-1D), or PA 66 (series 2A-2D), or PEBA (series 4A-4D), or amixture of polyamide and polypropylene (series 5A-5D), or of COPE(series 8A-8D).

On these samples, one in fact measures the post-shrinkage as shown inFIGS. 10A and 10B. The post-shrinkage is the difference between thedimensions of the injected part cooled to ambient temperature and thedimensions of this part after a recooking at a given temperature for acertain time. Here, the molded plates measure 50 mm×40 mm and they havea thickness of 2 mm, which means that in FIG. 10A, Y=40 mm and X=50 mm.By then measuring the dimensions Y′ and X′ as indicated in FIG. 10B, theshrinkage is represented by the formula:

shrinkage=ΔX=X−X′ and ΔY=Y−Y′.

The shrinkage measurements are only carried out on the platelets thatwere subjected to the high-temperature cycle, that is heating in an ovenfor 30 min at 195° C., because it is during this cycle that the mostextensive deformations are recorded.

The results of these shrinkage measurements are reported below in Table3.

The measurements of the shrinkage were not carried out on the sampleswhose component forming the framework was polyamide 11 (series 3A-3D)because the platelets flowed through the perforation. They also were notcarried out on the platelets whose framework was POM, because theseplatelets flowed through the perforation. In the same manner, thesemeasurements were not carried out when the framework was a mixture ofpolypropylene and of a terpolymer of ethylene-propylene-diene, for thesame reason. Also, these measurements were not carried out on thesamples in which the framework was acrylonitrile-butadiene-styrene, forthe same reason.

The results of the shrinkage measurements obtained on the samplesremaining after the passage through the oven for 30 min at 195° C. arereported in Table 3 below.

TABLE 3 X′ in mm Y′ in mm ΔX in mm ΔY in mm SomΔ in mm FRAMEWORK: PA 61A 39.40 49.22 0.60 0.78 1.38 1B 39.40 49.05 0.60 0.95 1.55 1C 37.7548.65 2.25 1.35 3.60 1D 31.41 41.22 8.59 8.78 17.37 FRAMEWORK: PA 66 2A40.00 49.40 0.00 0.60 0.60 2B 38.73 48.34 1.27 1.66 2.93 2C 39.80 47.820.2 2.18 2.38 2D 34.12 42.32 5.88 7.68 13.56 FRAMEWORK: PEBA 4A 37.9048.17 2.10 1.83 3.93 4B 39.55 49.84 0.45 0.16 0.61 4C 35.23 43.94 4.776.06 10.83 4D 33.02 41.00 6.98 9.00 15.98 FRAMEWORK: alloy PA/PP 5A35.42 46.41 4.58 3.59 8.17 SB 35.02 44.18 4.95 5.82 10.77 5C 31.18 41.028.82 8.98 17.80 5D 34.40 44.23 5.60 5.77 11.37 FRAMEWORK: COPE (esterblock polyether) 8A 36.26 47.95 3.74 2.05 5.79 8B 35.09 43.52 4.91 6.4811.39 8C 35.72 44.63 4.28 5.37 9.65 8D 35.87 45.55 4.13 4.45 8.58

The measurements of the deflection were also carried out on the samesamples.

The deflection was measured as shown in FIGS. 11A and 11B.

Thus, a sample specimen noted A manufactured from one of the testedcompositions is placed on a metal support 4 and the assembly is passedthrough the oven. FIG. 11A shows the specimen A on the support 4 beforepassage through the oven, and FIG. 11B shows the same specimen A on thesupport 4, after passage through the oven.

The deflection corresponds to the value Z represented in FIG. 11B.

The results, in mm, of this deflection measurement on the samples arereported in Table 4 below in which “B.T.” denotes a passage through theoven at low temperature, that is for 30 min at 140°C., “H.T.” denotes apassage through the oven at high temperature, that is for 30 min at195°C., “+deflection” represents the sum of the deflections “B.T.” and“H.T.,” and “+family” denotes the sum of the “+deflection” per frameworkfamily.

TABLE 4 B.T. H.T. “+deflection” “+family” FRAMEWORK: PA 6 1A 0.51 0.691.20 11.09 1B 1.26 2.91 4.17 1C 0.00 1.63 1.63 1D 2.02 2.07 4.09FRAMEWORK: PA 66 2A 0.72 1.06 1.78 23.03 2B 3.15 6.64 9.79 2C 1.01 1.212.22 2D 3.37 5.87 9.24 FRAMEWORK: PEBA 4A 2.53 0.51 3.04 6.92 4B 0.001.26 1.26 4C 0.00 0.00 0.00 4D 0.6 2.02 2.62 FRAMEWORK: alloy PA/PP 5A0.87 3.82 4.69 20.92 5B 0.56 2.1 2.66 5C 2.98 3.59 6.57 5D 4.86 2.147.00 FRAMEWORK: COPE (ester block polyether) 8A 0.00 0.56 0.56 0.56 8B0.00 0.00 0.00 8C 0.00 0.00 0.00 8D 0.00 0.00 0.00

One can see from the results of Tables 3 and 4 that only thecompositions in which the framework is either PEBA (amide blockpolyether) or COPE (ester block polyether) present the requiredqualities both in terms of shrinkage and deflection, that is in terms ofdeformation at high temperature.

However, in the family in which the framework is PEBA, when the adhesiveis a copolymer of ethylene-vinyl acetate, the deflection is too high. Inthe same manner, when the adhesive is a terpolymer of ethylene-acrylicester-maleic anhydride, the shrinkage is too high to be satisfactory.

Also, one can see from the preceding Tables 1-4 that with thecompositions in which the framework is COPE and the adhesive a copolymerof vinyl acetate or a copolymer of ethyleneacrylic ester, there is noadhesion to a metal support.

In conclusion, the only compositions presenting the required propertiesin terms of resistance to temperature, shrinkage, adhesion anddeflection are the specimens whose compositions are as follows: 4B, 4C,8B and 8D, that is compositions comprising as adhesive a copolymer ofethylene-vinyl acetate grafted with maleic anhydride or a copolymer ofethyleneacrylic ester or a terpolymer of ethylene-acrylic ester-maleicanhydride and, as framework component, either an ester block polyether(COPE) or an amide block polyether (PEBA).

However, to be usable for the manufacture of a closing stopper accordingto the invention, these compositions must also have the followingadditional and indispensable properties: suitability for molding intoany shape, sealing against water and pressure, and preservation of allthe above properties in a temperature range from −40° C. to +80° C.

The four compositions 4B, 4C, 8B and 8D could be molded by known methodsof the prior art, but only the compositions 4B and 8B presented anacceptable deformation at high temperature when molded to form closingdevices.

The following test therefore was carried out to demonstrate thesuperiority of these compositions 4B and 8B. Thus, closing devices wereobtained by molding to a closing diameter of 40 mm. A closing devicemanufactured from each of the compositions 4C, 4D, 8B and 8D wasprepared.

These sample closing devices are placed on metal plates which arerepresentative of the metal support to which they are preferablyapplied. These metal supports may or may not have been subjected to asurface treatment, for example, an anticorrosive treatment, such as acataphoresis coating.

As one can see in FIG. 3D, such a single-material closing device is aclosing device which comprises hooking tabs 3 and sealing lip 2.

In FIG. 3E, which is a cross-sectional view along the axis IIIE—IIIE ofFIG. 3D, one can also see the body 1 which is made of the same materialas the hooking tabs 3 and the sealing lip 2.

FIG. 3F represents a top view of the closing device represented in FIGS.3D and 3E.

FIG. 6B shows the closing device manufactured from the composition 8Bmounted on a perforated plate, that is before passage through the oven,while FIG. 6A shows the same closing device after passage through anoven. As one can see, the deformation and the change in color areslight.

In comparison, a sample of the composition 5D is also shown in FIG. 6A.This sample presents a strong deformation and a strong change in color.

Then, each one of the four above mentioned samples is placed on a roundperforated plate as shown in FIG. 7 under the name of “part beforepassage through an oven.”

Each one of these samples was then passed through the oven at hightemperature, that is for 30 min at 195° C.

As one can see in FIG. 7, the sample 4B presents few deformations aftersuch a temperature cycle.

Each one of the samples 4B, 4C, 8B and 8D was treated in the same mannerand, after cooling, the deflections were measured for each one of thesesamples.

The results of these measurements are reported in Table 5 below.

TABLE 5 SAMPLE DEFLECTION 4B  0.00 mm 4C 11.32 mm 8D 12.09 mm 8D  9.36mm

A test of the water sealing was then carried out on each specimenssubjected to the passage through an oven at high temperature.

This test of the seal against water was carried out as shown in FIGS. 8Aand 8B, that is first with the closing device in the vertical positionand then with the closing device in the horizontal position.

In this test one subjects, in a vertical position, and then in ahorizontal position, the closing device noted A in FIGS. 8A and 8B, to ahydrostatic pressure of 0.1 bar for 1 h to observe the possibleexistence of leaks.

In FIGS. 8A and 8B, the closing device mounted on the support is notedA, the support is noted B; the vat containing the water and allowing theapplication of hydrostatic pressure of 0.1 bar is noted C. The referenceD represents a flexible connection which brings the water into the vatC, the reference E represents a water column having a 100 cm heightwhich allows the obtention of the pressure of 0.1 bar in the vat C.

To be usable for the purposes of the invention, the closing device mustnot present any leak after having been exposed for at least 1 h to ahydrostatic pressure of 0.1 bar.

Only the specimens 4B and 8B, that is those manufactured from thecompositions of the invention successfully passed this test.

Finally, as mentioned initially, the closing device according to theinvention must adhere to its support, which is preferably a metalsupport.

For this purpose, and to demonstrate again the superiority of thecomposition of the invention, the resistances to detachment of theclosing devices obtained from the compositions 4B and 8B according tothe invention and those of the closing devices obtained fromcompositions that do not enter in the context of the invention, weremeasured, after passage through an oven at high temperature of theseclosing devices mounted on a metal plate. The tests were carried out atambient temperature on an apparatus shown in FIG. 9.

As represented in FIG. 9, a cylindrical punching rod G having a diameterof 10 mm is fixed to one of the plates of a compression machine so thatthe axis of the rod is perpendicular to the plane of the closing devicesA made of the different compositions tested.

The closing device is a plate having the dimensions 50 mm×40 mm, and athickness of 2 mm, which has been subjected to one cycle in an oveneither at low temperature or at high temperature.

The closing device is maintained by the specimen carrier noted H in FIG.9. It is a steel plate with an oblong perforation having the dimensions40 mm×20 mm. The thickness of the specimen carrier is 1 mm.

One measures the force required to detach the closing device A from thespecimen carrier H.

These tests were carried out on each of the samples of the series 1A-1D,the series 2A-2D, the series 4A-4D, the series 5A-5D and the series8A-8D.

The results of these tests are reported in Table 6 below.

In this table “B.T.” denotes a thermal cycle in an oven at lowtemperature, that is for 30 min at 140° C., and “H.T.” denotes a cycleat high temperature in the oven, that is a 30-min passage at 195° C. andthe numerical value reported represents the force required to detach theclosing device A.

TABLE 6 SAMPLE FORCE AFTER B.T. FORCE AFTER H.T. 1A — 6.5 daN 1B 30 daN45 daN 1C 1 daN 5 daN 1D — 10 daN 2A 3.5 daN 8.5 daN 2B >40 daN >40 daN2C 1.5 daN 3 daN 2D 5 daN 9 daN 4A 3 daN 9 daN 4B 5.5 daN 15 daN 4C 0.5daN 6 daN 4D 6.5 daN 13 daN 5A 12 daN 20 daN 5B 13 daN 25 daN 5C 11 daN4 daN 5D 4 daN 4.5 daN 8A — 3.5 daN 8B 14 daN 24 daN 8C — 4 daN 8D 8 daN20 daN

One can see from the results reported in Table 6 taken in combinationwith the results reported in Tables 1-5 that the compositions 4B and 8Bare the only ones that have all the required properties. The deformationat high temperature (shrinkage, deflection) being a very importantcriterion, the preferred composition of the invention is the composition4B.

The sample 4B corresponds to a composition comprising 75 wt % of anadhesive component which is a polymer of ethylene-vinyl acetate graftedwith maleic anhydride, comprising 14 wt % of vinyl acetate units, 0.5-1wt % of maleic anhydride, the remainder being ethylene, and 25 wt % ofan amide block polyether whose amide blocks are Nylon® 6, that ispolyamide 6 obtained by condensation of ε-caprolactam, and whose ethersegments are based on ethylene glycol with a small amount of propyleneglycol.

The sample 8B corresponds to a closing device manufactured from acomposition containing 75 wt % of an adhesive which is the same polymerof ethylene-vinyl acetate grafted with maleic anhydride as above, and 25wt % of a framework component which is an ester block polyether whoseester part consists of polybutylene terephthalate and whose ether partconsists of units of ethylene glycol.

In this composition, the adhesive component has a melting temperature of95° C. and the component forming the framework has a melting temperatureof 207° C.

Thus, this composition started to present an acceptable adhesion afterpassage through an oven at 100° C. with the drawback of requiring anincrease in the residence time to 1 h. In the same manner, the closingstopper made from this composition maintained its shape after a passagethrough an oven at 200° C. for 15 min.

Tests were also carried out with a composition still containing asadhesives the same polymer of ethylene-vinyl acetate grafted with maleicanhydride and where the framework component was the same amide blockpolyether as in the composition 4B, except that it was modified by acopolymer of ethylene-propylene.

The test was also carried out using as adhesive the same polymer ofethylene-vinyl acetate grafted with maleic anhydride and the amide blockpolyether used for the sample 4B but in a mixture with a terpolymer ofethylene-propylene diene. The results were also excellent.

In the same manner, tests were carried out using as adhesive the samepolymer of ethylene-vinyl acetate grafted with maleic anhydride whichwas in addition modified by a grafting of polyethylene or ofpolypropylene, and a framework component consisting either of PEBA or ofCOPE. The results obtained were also excellent.

Tests were also carried out using as adhesive a polymer ofethylene-vinyl acetate-maleic anhydride obtained by the directpolymerization of the constituent monomers and using as frameworkcomponent either PEBA or COPE. The results obtained were also excellent.

Moreover, the relative proportions of vinyl acetate, of ethylene and ofmaleic anhydride of the adhesive component were varied. One thenobserves that the properties of the composition of the invention werealways good when the adhesive component contained 0.5-40 wt % of vinylacetate and 0.5-15 wt % of maleic anhydride, the remainder beingethylene. However, they were slightly better when the adhesive componentcontained 5-25 wt % of units of vinyl acetate and 0.5-10 wt % of maleicanhydride, the remainder being ethylene.

Outside of the lower and upper weight limits for each of the components,indicated above, the properties of adhesion and maintenance of the shapeof the manufactured piece were lost.

However, the preferred adhesive remains the adhesive described for thecompositions 4B and 8B.

Tests were also carried out with an adhesive component consisting of acopolymer of ethylene-vinyl acetate not grafted or copolymerized withmaleic anhydride but modified, instead, to contain epoxy functions. Theresults were also good. The best results were obtained when the epoxyfunctions were contributed by glycidyl methacrylate or an acrylic acidor a methacrylic acid. It is preferred, in this case, to use glycidylmethacrylate at 1-10 wt %.

However, in the most preferred composition of the invention, theadhesive is a copolymer of ethylene-vinyl acetate grafted with maleicanhydride having a content by weight of vinyl acetate units of 14% and acontent by weight of maleic anhydride of 0.5-1%, the remainder beingethylene and the preferred amide block polyether used in the inventionis an amide block polyether in which the amide blocks consist ofpolyamide 6 and the ether segments are based on ethylene glycol and/orpropylene glycol.

When used in a mixture with the terpolymer ethylene-propylene-diene, thepreferred diene is butadiene.

Finally, when the framework component is an ester block polyether as inthe composition 8B, the ester part preferably consists of poly(butyleneterephthalate) (PBTP) whose ether part consists of units of ethyleneglycol and/or propylene glycol.

In the same manner, excellent results were obtained when the ratio byweight of the adhesive component to the framework component varied from80:20 to 50:50, although, when the framework component is PEBA or amixture of PEBA with another component as defined above, the preferredratio by weight is 75:25.

In contrast, when the framework component is an ester block polyetherwhose ester part consists of polybutylene terephthalate (PBTP) and whoseether part consists of units of ethylene glycol and/or propylene glycol,the preferred ratio by weight of the adhesive component to the frameworkcomponent is 60:40.

Thus, a composition as defined above presents excellent qualities ofheat resistance, pressure sealing, and adhesion to any metal support.The composition of the invention can also contain any required additivewhich imparts other properties to it.

Such additives are well known in the art and, for example, one canmention: the “tackifying” resins, that is those which impart stickinessto the touch, fire resistant agents, reinforcement materials, volumefillers or antistatic or fungicidal fillers, antioxidants, stabilizersagainst decomposition in light or heat, or dyes.

The adhesives can be added alone or in mixtures of several adhesives.

They are usually added in quantities of approximately 0.03-5 wt %, butany quantity that confers the desired additional properties to thecomposition of the invention, without harmful effect on its remarkableproperties, can be used.

The preferred fire retardant agents include fire retardant agents of thehalogen type, such as tetrabromobenzene, phosphate derivatives such aschloroalkyl phosphates; hydrated alumina or hydrated magnesium oxide.

As reinforcement material used in the invention one can use fibers,flakes or beads made of glass, carbon or mica. The preferred charges aretalc, chalk and silica.

The preferred tackifying resins include resins of the phenol terpenetype whose addition imparts a stickiness to the touch at low or hightemperatures.

As will be seen below, a preferred tackifying resin is a resin thatconfers stickiness to the touch at cold temperature, of the glycol estertype.

More particularly, a preferred resin which is particularly advantageousis a resin of the ethylene glycol ester or propylene glycol ester type.

A colophony derivative esterified with ethylene glycol or propyleneglycol is even more advantageous.

The composition of the invention can thus advantageously be used for themanufacture of closing devices to close any opening in any type ofsupport and in particular in a metal support, and to achieve sealingagainst water, pressure and dust of this closing device.

This closing device can be as represented in FIGS. 3A-3F which havealready been discussed.

However, this closing device can also be as represented in FIGS. 3G and3H, that is without hooking tab but with a groove 6 provided in the body1 of the closing device to maintain it in place in the opening.

However, the closing stopper manufactured from the composition of theinvention being flexible, the presence of hooking tabs or the presenceof a groove is not necessary because the closing stopper of theinvention can close the opening and be maintained in place, beforepassage through an oven by elastic embedding in the opening.

These two types of closing devices represented in FIGS. 3A-3H can beprepared by injection molding of the composition of the invention.

The composition of the invention can be used for injection moldingeither by simultaneous injection, in the desired proportions, of pelletsof the adhesive component and of pellets of the framework formingcomponent and of the desired additives, or by first thoroughly mixingall these components, melting, and reconversion to pellets of thecomposition formed, followed by the injection of the composition soformed.

Another embodiment variant of the closing stopper of the invention isrepresented in FIGS. 4A and 4B.

As one can see in these figures, the closing stopper of the invention ofthe invention [sic] consists of a simple plate 7 having dimensions whichare larger than the opening to be closed, plate 7 being coated over atleast one of its faces with a film 8 consisting of the composition ofthe invention containing a resin which is sticky to the touch at coldtemperature, such as a resin of the glycol ester type, preferablyethylene glycol ester or propylene glycol ester.

It is preferred that the resin which is sticky to the touch at coldtemperature be present in quantities of 0.2-10 wt % with reference tothe total weight of the composition.

This embodiment variant is particularly advantageous because the film 8then presents stickiness at cold temperature and thus ensures the selfmaintenance of the closing stopper on the support 4 with the opening tobe closed, before the passage through an oven.

This film 8 preferably has a thickness of 0.3-3 mm.

The plate 7 which, over at least one of its faces, presents this film 8,can also have a small thickness such as 0.5-5 mm.

Thus, this embodiment variant of the invention presents two additionaladvantages, the first being that the closing stopper so prepared matchesthe shape of its support 4 because of its flexibility and the secondbeing that the closing stopper so prepared occupies a small volume incomparison to a conventional closing device.

The plate 7, onto which is placed the film 8, that is, the compositionof the invention containing a resin which imparts stickiness to thetouch at cold temperature, can be made of any desired material providedthat it does not decompose or melt or become excessively viscous at theabove defined temperatures of passage through an oven.

Thus, it can consist of a composition of the invention which may or maynot contain tackifying resins.

It can also consist of specific materials that impart specificproperties to the closing device of the invention.

For example, the plate 7 can be a metal plate when electrical propertiesare sought.

It can be an elastomer, which will confer improved properties ofacoustic filtration to the closing stopper of the invention,particularly when a honeycombed elastomer is used. In this case, theclosing stopper also has improved friction properties, that is, slidingwill be reduced.

If one wishes, on the other hand, to increase the sliding properties ofthe closing stopper, then a plate 7 consisting ofpolytetrafluoroethylene (PTFE) is used.

If one wishes to increase the rigidity of the closing stopper of theinvention, a plate 7 is used which is made of a rigid plastic of thepolyamide type or polyamide and propylene alloy type, for example.

The plate 7 can also consist of a hot melt composition containing anagent which expands at high temperature, preferably at a temperatureequal to the minimum temperature of the currently used ovens, that is140° C.; this type of closing stopper can be made, for example, bycoextrusion of the plate 7 and the film 8.

In all cases, after the passage through the oven, the adhesion iscarried out thanks to the melting of the adhesive component and itssubsequent hardening.

The closing stopper of the invention will preserve an acceptable shapeas shown in FIG. 7 thanks to the framework forming component, after thepassage through the oven.

Although the invention was described with reference to embodimentexamples of a stopper having a cylindrical closing shape, it is in noway limited to these examples. Thus, because of the excellent propertiesof suitability to molding of the composition of the invention, theclosing stopper can also assume any shape other than the describedcylindrical shape.

In addition, the thermogluing composition of the invention clearly canbe used for manufacturing any other part besides a closing stopper andfor other another use, for example, like the manufacture of foodpackaging films or to effect acoustical insulation of parts without anyopening.

In the same manner, the time/temperature pairs given here are thosecurrently used, but, as already indicated, these pairs could be modifiedas long as the properties of adhesion and preservation of shape of theparts manufactured from the compositions of the invention will bemaintained.

Accordingly, the composition of the invention can have numerousapplications which will be readily apparent to an ordinary personskilled in the art.

What is claimed is:
 1. A thermogluing composition comprising an adhesivecomponent and a framework forming component wherein: a) the adhesivecomponent is chosen from the group consisting of a polymer ofethylene-vinyl acetate (EVA)-maleic anhydride, optionally modified withpolyethylene or polypropylene, and a polymer of ethylene-vinyl acetate(EVA) modified to have epoxy functions, and b) the framework formingcomponent is chosen from the group consisting of an ester blockpolyether (COPE) and, an amine block polyether (PEBA) optionally in amixture with a copolymer of ethylene-propylene, said copolymer ofethylene-propylene optionally being at least partially replaced by aterpolymer of ethylene-propylene-diene (EPDM).
 2. The thermogluingcomposition according to claim 1, including said polymer ofethylene-vinyl acetate-maleic anhydride containing 0.5-40 wt % of vinylacetate units and 0.05-15 wt % of maleic anhydride, the remainder beingethylene.
 3. The thermogluing composition according to claim 1,including said polymer of ethylene-vinyl acetate-maleic anhydridecontaining 5-25 wt % of vinyl acetate units and 0.5-10 wt % of maleicanhydride, the remainder being ethylene.
 4. The thermogluing compositionaccording to claim 1, including said copolymer of ethylene-vinylacetate-maleic anhydride containing 14 wt % of vinyl acetate units and0.5-1 wt % of maleic anhydride, the remainder being ethylene.
 5. Thethermogluing composition according to claim 1, including said polymer ofethylene-vinyl acetate-maleic anhydride wherein said polymer ofethylene-vinyl acetatemaleic anhydride is a copolymer of ethylene-vinylacetate grafted with maleic anhydride.
 6. The thermogluing compositionaccording to claim 1, including said polymer of ethylene-vinyl acetatemodified to have epoxy functions, the epoxy functions being contributedby one of glycidyl methacrylate, an acrylic acid, and methacrylic acid.7. The thermogluing composition according to claim 6, including 1-10 wt% of glycidyl methacrylate.
 8. The thermogluing composition according toclaim 1, wherein said framework forming component is an ester blockpolyether (COPE) having an ester part consisting of the poly(butyleneterephthalate) (PBTP) and an ether part consisting of at least one ofethylene glycol and propylene glycol units.
 9. The thermogluingcomposition according to claim 8, wherein the ratio by weight betweensaid adhesive component and said ester block polyether is 60:40.
 10. Thethermogluing composition according to claim 1, wherein said frameworkmaterial is a mixture of PEBA and at least one of a copolymer ofethylene-propylene and a terpolymer of ethylene-propylene-diene, andPEBA consists of nylon-6 blocks and ether segments based on at least oneof ethylene glycol an propylene glycol, and the diene of the terpolymerof ethylene-propylene-diene, when present, is butadiene.
 11. Thethermogluing composition according to claim 10, wherein the ratio byweight between said adhesive component and said framework formingcomponent is 75:25.
 12. The thermogluing composition according to claim1, wherein the ratio by weight between said adhesive component and saidframework forming component is between 80:20 and 70:30.
 13. Thethermogluing composition according to claim 1, including additivesselected from the group consisting of resins which confer stickiness tothe touch, fire retardant agents, reinforcement agents, antistaticagents, antifungicides, antioxidants, stabilizers to light and heat,dyes, fillers, and mixtures thereof.
 14. The thermogluing compositionaccording to claim 1, including a resin which confers stickiness to thetouch at cold temperatures.
 15. The thermogluing composition accordingto claim 14, wherein said resin which confers a stickiness to the touchat cold temperature is a glycol ester resin.
 16. The thermogluingcomposition according to claim 15, wherein said glycol ester resin isone of a diethylene glycol ester, a dipropylene glycol ester, and aglycol ester derivative of colophony.
 17. The thermogluing compositionaccording to claim 14, containing 0.2-10 wt % of said resin, withreference to the total weight of the composition.
 18. A stopper forclosing an opening of a support, including a plate larger than theopening to be closed, having a melting and/or decomposition temperaturewhich is higher than a maximum temperature used to glue the stopper tothe support and wherein the plate is coated over at least one face witha film comprising the composition according to claim
 14. 19. The stopperaccording to claim 18, wherein the plate is formed from a compositioncomprising an adhesive component and a framework forming componentwherein: a) the adhesive component is chosen from the group consistingof a polymer of ethylene-vinyl acetate (EVA)-maleic anhydride,optionally modified with polyethylene or polypropylene, and a polymer ofethylene-vinyl acetate (EVA) modified to have epoxy functions; and b)the framework forming component is chosen from the group consisting ofan ester block polyether (COPE), and an amine block polyether (PEBA)optionally in a mixture with a copolymer of ethylene-propylene, saidcopolymer of ethylene-propylene optionally being at least partiallyreplaced by a terpolymer of ethylene-propylene-diene (EPDM).
 20. Thestopper according to claim 18, wherein the plate is a material chosenfrom the group consisting of a metal, an elastomer, a honeycombedelastomer, a rigid plastic, polytetrafluoroethylene, and a hot meltcomposition containing an expansion agent which decomposes at atemperature of at least 140° C.
 21. The stopper according to claim 18,wherein the plate has a thickness of 0.5-5 mm and the film has athickness of 0.3-3 mm.
 22. A stopper for closing an opening of a supportcomprising a composition according to claim
 1. 23. The stopper accordingto claim 22 comprising a surface having dimensions which are larger thanthose of the opening to be closed as well as means for hooking,insertable into the opening.
 24. The stopper according to claim 22,wherein the support is a metal support.